Costa Rica

Costa Rica – Biogeochemical Landscapes on the Osa Peninsula

I’ve worked in Costa Rica on and off since graduate school, but I’m really excited about this new project in collaboration withAlan Townsend,Cory Cleveland,Greg AsnerandRobert Anderson. We’re focusing on the Osa Peninsula, in southern Costa Rica. Alan and Cory have worked there for years – documenting that these super wet (5-8m/yr rainfall) lowland forests behave quite differently biogeochemically than montane forests that are similarly wet.

One of the cool things about the Osa is that it is undergoing rapid tectonic uplift as it’s being lifted out of the ocean. As a result, the geomorphology is complex. Some portions of this landscape have adjusted to their new position, and others have not. This landscape disequilibrium seems to have imposed interesting biogeochemical patterns, some really nice work bySamantha Wientraubhas shown distinct differences in N cycling across geomorphic gradients. Our project seeks to build on this. We’ll be working across geomorphic and climatologic gradients in the Osa, asking how these affect N cycling, nutrient status and limitation.

We are very lucky to have data from theCarnegie Airborne Observatory, which flew six flight lines over Osa in 2011. This unique instrument combines LIDAR with hyperspectral remote sensing, and can determine ground topography, canopy height and structure, and canopy chemistry from an aircraft based platform. These data allow us to see individual tree crowns, and understand their chemical properties (nitrogen, pigments, water content, lots more). These data will allow us to explore the interaction between trees, climate, and the geomorphology of the landscape in a way that has never been done in any tropical forest.

Above left – the six flight lines of the CAO over Osa. Above right – example data from one of the flight lines. Top panel shows canopy height, middle panel shows ground height (e.g. trees removed), and bottom panel shows canopy structure from a side view. Data courtesy of the Carnegie Airborne Observatory and the Carnegie Institution for Science.